1. Field of the Invention
This invention relates generally to new hybrid cell lines and more specifically to hybrid cell lines for production of monoclonal antibody to an antigen found on activated human lymphocytes, the interleukin-2-receptor, to the antibody so produced, and to therapeutic and diagnostic methods and compositions employing this antibody.
2. Background Information
For many, if not all cells, the initial trigger for proliferation appears to be the interaction of growth factors with the cell surface growth factor receptor. Activation of the growth factor receptor leads in turn to yet undefined cytoplasmic signalling systems.
Resting T lymphocytes are long living cells in the G.sub.o phase of the cell cycle. They only enter proliferative cycles under antigenic stimulation in the presence of a T cell growth factor, interleukin 2 (IL-2). Receptors for IL-2 are not detectable on the surface of resting T cells. Expression of IL-2 receptors (IL-2R) is the consequence of interaction of antigen with cells having the antigen receptor. As shown recently, IL-2 receptor expression is a transient event and repeated restimulation by lectins (Cantrell, P. A., and K. A. Smith, (1984), Science (Wash. D.C.) 224; 1312); (Osawa, H., and Diamantstein, T. (1984) J. Immunol.,132,2445) or the antigen (Reske-Kunz, A. B., D. v. Steldern, E. R ude, H. Osawa and T. Diamantstein, (1984), J. Immunol.,133, 1356) is required for continuous IL-2 receptor expression and consequently for long term cell growth.
Since IL-2-R is expressed exclusively on activated lymphocytes, a monoclonal antibody (mAb) that reacts with the IL-2-R may be useful as a specific and selective immunosuppressive agent. Furthermore, such antibodies may serve as diagnostic reagents to detect qualitatively and quantitatively activated lymphocytes as well as neoplastic cells expressing IL-2-R.